Publications (82)
The nearby luminous transient AT2018cow: a magnetar formed in a sub-relativistically expanding non-jetted explosion
P. Mohan, T. An, J. Yang
The fast-rising blue optical transient AT2018cow indicated unusual early phase characteristics unlike relatively better studied explosive transients. Its afterglow may be produced…
The Quasar CTD 135 is Not a Compact Symmetric Object
S. Frey, K. Ã. Gabányi, T. An
The radio-loud quasar CTD 135 (2234+282, J2236+2828) has been proposed as a candidate compact symmetric object (CSO), based on its symmetric radio structure revealed by multi-frequ…
Imaging and variability studies of CTA~102 during the 2016 January -ray flare
Xiaofeng Li, P. Mohan, T. An +6
The -ray bright blazar CTA 102 is studied using imaging (new 15 GHz and archival 43 GHz Very Long Baseline Array, VLBA data) and time variable optical flux density, polarizatio…
The rise and fall of a binary AGN candidate: the story of PSO J334.2028+1.4075
P. Benke, S. Frey, K. Ã. Gabányi +7
Apparently periodic optical variations of the luminous high-redshift (z=2.06) quasar PSO J334.2028+1.4075 led Liu et al. (2015) to interpret the variability as the orbital period o…
The Most Compact Bright Radio-loud AGN -- II. VLBA Observations of Ten Sources at 43 and 86~GHz
X. -P. Cheng, T. An, X. -Y. Hong +10
Radio-loud active galactic nuclei (AGNs), hosting powerful relativistic jet outflows, provide an excellent laboratory for studying jet physics. Very long baseline interferometry (V…
Is 4C+29.48 a gamma-ray source?
K. Ã. Gabányi, S. Frey, T. An
The Fermi Large Area Telescope revealed that the extragalactic gamma-ray sky is dominated by blazars, active galactic nuclei (AGN) whose jet is seen at very small angle to the line…
A single radio-emitting nucleus in the dual AGN candidate NGC 5515
K. Ã. Gabányi, S. Frey, T. Xiao +4
The Seyfert galaxy NGC 5515 has double-peaked narrow-line emission in its optical spectrum, and it has been suggested that this could indicate that it has two active nuclei. We obs…
Acoustic spin pumping: Direct generation of spin currents from sound waves in Pt/Y3Fe5O12 hybrid structures
K. Uchida, H. Adachi, T. An +5
Using a Pt/Y3Fe5O12 (YIG) hybrid structure attached to a piezoelectric actuator, we demonstrate the generation of spin currents from sound waves. This "acoustic spin pumping" (ASP)…
Square Kilometre Array Science Data Challenge 1: analysis and results
A. Bonaldi, T. An, M. Bruggen +42
As the largest radio telescope in the world, the Square Kilometre Array (SKA) will lead the next generation of radio astronomy. The feats of engineering required to construct the t…
Square Kilometre Array Science Data Challenge 3a: foreground removal for an EoR experiment
A. Bonaldi, P. Hartley, R. Braun +179
We present and analyse the results of the Science data challenge 3a (SDC3a, https://sdc3.skao.int/challenges/foregrounds), an EoR foreground-removal community-wide exercise organis…
Multi-wavelength view of the close-by GRB 190829A sheds light on gamma-ray burst physics
O. S. Salafia, M. E. Ravasio, J. Yang +12
Gamma-ray bursts are produced as a result of cataclysmic events such as the collapse of a massive star or the merger of two neutron stars. We monitored the position of the close-by…
Unique Science Opportunities for Space VLBI Systems with the SKA Telescopes
Y. Y. Kovalev, G. Bruni, T. An +17
To date, two dedicated Space Very Long Baseline Interferometry (SVLBI) missions, the VLBI Space Observatory Programme (VSOP) and RadioAstron, have provided groundbreaking insights…
The Detection of a Compact Radio Feature in a Seyfert Galaxy After an Accretion Rate Change
K. Ã. Gabányi, K. Smith, S. Frey +3
X-ray binaries are known to show state transitions related to accretion rate changes which are often accompanied with dramatic changes in the jet emission. However, it is not clear…
Magnetically Driven Relativistic Jet in the High-Redshift Blazar OH~471
S. Guo, T. An, Y. Liu +15
Context : Understanding the mechanisms that launch and shape powerful relativistic jets from supermassive black holes (SMBHs) in high-redshift active galactic nuclei (AGN) is cruci…
The OH Megamaser Emission in Arp\,220: the rest of the story
W. A. Baan, J. N. H. S. Aditya, T. An +1
The OH Megamaser emission in the merging galaxy Arp220 has been re-observed with the Multi-Element Radio Linked Interferometer Network (MERLIN) and the European VLBI Network (EVN).…
Radio-loud Quasars above Redshift 4: VLBI Imaging of an Extended Sample
M. Krezinger, K. Perger, K. Ã. Gabányi +7
High-redshift radio sources provide plentiful opportunities for studying the formation and evolution of early galaxies and supermassive black holes. However, the number of known ra…
White Paper on East Asian Vision for mm/submm VLBI: Toward Black Hole Astrophysics down to Angular Resolution of 1~R
K. Asada, M. Kino, M. Honma +35
This White Paper details the intentions and plans of the East Asian Very Long Baseline Interferometry (VLBI) community for pushing the frontiers of millimeter/submillimeter VLBI. T…
VLBI observation of the newly discovered z=5.18 quasar SDSS J0131-0321
K. E. Gabanyi, D. Cseh, S. Frey +4
Few high-redshift, radio-loud quasars are known to date. The extremely luminous, radio-bright quasar, SDSS J013127.34-032100.1 was recently discovered at a redshift of . We…
Three little radio galaxies in the early Universe
K. Ã. Gabányi, S. Frey, Z. Paragi +7
Volonteri et al. (2011) found that the number of radio-loud quasars above redshift 4 calculated from the luminosity function (based upon Swift/BAT observations) is much smaller tha…
VLBI observations of four radio quasars at : blazars or not?
H. -M. Cao, S. Frey, K. Ã. Gabányi +5
Blazars are active galactic nuclei (AGN) whose relativistic jets point nearly to the line of sight. Their compact radio structure can be imaged with very long baseline interferomet…
Kinematics of the parsec-scale radio jet in 3C48
T. An, X. Y. Hong, M. J. Hardcastle +6
We present results on the compact steep-spectrum quasar 3C 48 from observations with the VLBA, MERLIN and EVN at multiple radio frequencies. In the 1.5-GHz VLBI images, the radio j…
Heat-induced damping modification in YIG/Pt hetero-structures
M. B. Jungfleisch, T. An, K. Ando +7
We experimentally demonstrate the manipulation of magnetization relaxation utilizing a temperature difference across the thickness of an yttrium iron garnet/platinum (YIG/Pt) heter…
From binary to singular: the AGN PSO J334.2028+1.4075 under the high-resolution scope
P. Benke, K. Ã. Gabányi, S. Frey +6
PSO J334.2028+1.4075 (PSO J334) is a luminous quasar located at redshift z=2.06. The source gained attention when periodic flux density variations were discovered in its optical li…
The radio core and jet in the broad absorption line quasar PG 1700+518
J. Yang, F. Wu, Z. Paragi +1
The blue-shifted broad absorption lines (BAL) or troughs are observed in Active Galactic Nuclei (AGNs) when our line of sight is intercepted by a high speed outflow (wind), likely…
An extremely soft and weak fast X-ray transient associated with a luminous supernova
W. -X. Li, Z. -P. Zhu, X. -Z. Zou +101
Long gamma-ray bursts (LGRBs), including their subclasses of low-luminosity GRBs (LL-GRBs) and X-ray flashes (XRFs) characterized by low spectral peak energies, are known to be ass…
Spin mixing conductance at a well-controlled platinum/yttrium iron garnet interface
Z. Qiu, K. Ando, K. Uchida +6
A platinum (Pt)/yttrium iron garnet (YIG) bilayer system with a well-controlled interface has been developed; spin mixing conductance at the Pt/YIG interface has been studied. Crys…
An energetic dirty fireball detected in soft X-rays
C. -Y. Dai, J. Quirola-Vásquez, Y. -H. Wang +76
The collapse of massive stars drives explosions that power relativistic fireballs. If only a small amount of matter is entrained, such clean fireballs can expand with Lorentz facto…
Multiwavelength quasi-periodic variability of the blazar Ton 599
Yu. V. Sotnikova, T. V. Mufakharov, A. E. Volvach +34
During the last 40-50 years, the TeV blazar Ton 599 has systematically experienced major outbursts detected in a wide wavelength range from radio to -rays. In this work, we pre…
The First Large Absorption Survey in HI (FLASH): I. Science Goals and Survey Design
J. R. Allison, E. M. Sadler, A. D. Amaral +27
We describe the scientific goals and survey design of the First Large Absorption Survey in HI (FLASH), a wide field survey for 21-cm line absorption in neutral atomic hydrogen (HI)…
Compact Bright Radio-loud AGNs -- III. A Large VLBA Survey at 43 GHz
X. -P. Cheng, T. An, S. Frey +12
We present the observational results from the 43-GHz Very Long Baseline Array (VLBA) observations of 124 compact radio-loud active galactic nuclei (AGNs) that were conducted betwee…
High-resolution radio observations of TeV candidate sources
J. KÅmÃves, K. Ã. Gabányi, S. Frey +3
Radio-loud active galactic nuclei (AGN) with their jets pointed close to our line of sight constitute the majority of extragalactic -ray sources and significantly contribute to…
The radio structure of 3C 316, a galaxy with double-peaked narrow optical emission lines
T. An, Z. Paragi, S. Frey +6
The galaxy 3C\,316 is the brightest in the radio band among the optically-selected candidates exhibiting double-peaked narrow optical emission lines. Observations with the Very Lar…
Dual AGN and Multiple SMBH Systems in the Era of SKAO
Q. D'Amato, L. Cui, R. Deane +23
We present a radio-oriented review of current strategies for the detection and characterization of dual active galactic nuclei (DAGN) and supermassive black hole binaries (SMBHBs),…
Four dual AGN candidates observed with the VLBA
K. Ã. Gabányi, T. An, S. Frey +4
According to hierarchical structure formation models, merging galaxies are expected to be seen in different stages of their coalescence. However, currently there are no straightfor…
Parsec-scale radio structure of 14 Fanaroff-Riley type 0 radio galaxies
X. -P. Cheng, T. An
Recently a population of compact radio galaxies were classified as Fanaroff-Riley type 0 radio galaxies (FR 0s). The physical nature of FR 0s and the connection with the classical…
From compact jets to extended lobes: radio morphologies of distant quasars at z > 4
K. Ã. Gabányi, M. Kunert-Bajraszewska, A. Krauze +9
High-redshift quasars play an essential role in studying the growth and evolution of supermassive black holes and active galactic nuclei (AGN). Radio-loud quasars additionally enab…
J2102+6015: an Intriguing Radio-loud Active Galactic Nucleus in the Early Universe
S. Frey, T. An, K. Gabányi +10
The powerful high-redshift quasar J2102+6015 (at z=4.575) may provide useful information for studying supermassive black hole growth, galaxy evolution and feedback in the early Uni…
The Polarisation Sky Survey of the Universe's Magnetism (POSSUM): Science Goals and Survey Description
B. M. Gaensler, G. H. Heald, N. M. McClure-Griffiths +57
The Australian SKA Pathfinder (ASKAP) offers powerful new capabilities for studying the polarised and magnetised Universe at radio wavelengths. In this paper, we introduce the Pola…
The radio structure of the peculiar narrow-line Seyfert 1 galaxy candidate J1100+4421
K. Ã. Gabányi, S. Frey, Z. Paragi +5
Narrow-line Seyfert 1 galaxies (NLS1) are an intriguing subclass of active galactic nuclei. Their observed properties indicate low central black hole mass and high accretion rate.…
The simultaneous VLA observations of Sgr A* from 90 to 0.7 cm
T. An, J. -H. Zhao, X. -Y. Hong +4
We present a spectrum of Sgr A* observed simultaneously on June 17, 2003 at wavelengths from 90 to 0.7 cm with the VLA. In the spectrum, we also include the measurements of Sgr A*…
The expansion of the GRB 221009A afterglow
S. Giarratana, O. S. Salafia, M. Giroletti +14
We observed -ray burst (GRB) 221009A using very long baseline interferomety (VLBI) with the European VLBI Network (EVN) and the Very Long Baseline Array (VLBA), over a period s…
Milliarcsecond-scale radio structure of the most distant BL Lac object candidate at redshift 6.57
S. Frey, Y. Zhang, K. Perger +7
The existence of accreting supermassive black holes up to billions of solar masses at early cosmological epochs (in the context of this work, redshifts z>=6) requires very fast gro…
Parsec-scale jet properties of the gamma-ray quasar 3C 286
T. An, B. -Q. Lao, W. Zhao +4
The quasar 3C~286 is one of two compact steep spectrum sources detected by the {\it Fermi}/LAT. Here, we investigate the radio properties of the parsec(pc)-scale jet and its (possi…
Four hot DOGs in the microwave
S. Frey, Z. Paragi, K. Ã. Gabányi +1
Hot dust-obscured galaxies (hot DOGs) are a rare class of hyperluminous infrared galaxies identified with the Wide-field Infrared Survey Explorer (WISE) satellite. The majority of…
SDSSJ110546.07+145202.4: The first long-duration radio changing-look NLS1 galaxy
S. Komossa, D. Grupe, A. Kraus +12
SDSSJ110546.07+145202.4 stands out as a unique radio changing-look Narrow-line Seyfert 1 (NLS1) galaxy that has brightened dramatically and shows an exceptionally long duration of…
High-redshift quasars at : radio variability and MPS/GPS candidates
Yu. Sotnikova, A. Mikhailov, T. Mufakharov +7
We present a study of the radio variability of bright, mJy, high-redshift quasars at on timescales up to 30-40 years. The study involved simultaneous RATA…
The radio counter-jet of the QSO 3C~48
W. X. Feng, T. An, X. Y. Hong +4
We present multi--frequency radio observational results of the quasar 3C~48. The observations were carried out with the Very Large Array (VLA) at five frequencies of 0.33, 1.5, 4.8…
Deep ASKAP EMU Survey of the GAMA23 field: Properties of radio sources
Gülay Gürkan, I. Prandoni, A. O'Brien +19
We present the Australian Square Kilometre Array Pathfinder (ASKAP) observations of the Galaxy and Mass Assembly (GAMA)-23h field. The survey was carried out at 887.5 MHz and cover…
Two in one? A possible dual radio-emitting nucleus in the quasar SDSS J1425+3231
S. Frey, Z. Paragi, T. An +1
The radio-emitting quasar SDSS J1425+3231 (z=0.478) was recently found to have double-peaked narrow [O III] optical emission lines. Based on the analysis of the optical spectrum, P…
Swift J1644+5734: the EVN view
Z. Paragi, J. Yang, S. Komossa +5
A small fraction of Tidal Disruption Events (TDE) produce relativistic jets, evidenced by their non-thermal X-ray spectra and transient radio emission. Here we present milliarcseco…
VLBI observations of VIK J2318-3113, a quasar at z = 6.44
Y. Zhang, T. An, A. Wang +5
The nature of jets in active galactic nuclei (AGN) in the early Universe and their feedback to the host galaxy remain a highly topical question. Observations of the radio structure…
Searching for a pair of accreting supermassive black holes in J1425+3231
K. Ã. Gabányi, S. Frey, Z. Paragi +2
In hierarchical structure formation scenarios, merging galaxies are expected to be seen in different phases of their coalescence. Simulations suggest that simultaneous activity of…
Evn, Merlin, and Vla Observations of Nrao530
X. Y. Hong, J. H. Zhao, T. An +4
We present images of NRAO530 observed with the EVN (VLBI) at 5 GHz, the MERLIN at 1 .6 and 5 GHz, and the VLA at 5 and 8 GHz showing the complex morphology on scales from pc to kpc…
SKAVLBI view of AGN jets in the early Universe
C. Spingola, M. Mezcua, Y. Liu +33
Active Galactic Nuclei (AGN) are among the brightest sources in the Universe, and those that are also jetted are uniquely valuable at the earliest epochs, because their relativisti…
High-resolution radio imaging of the gamma-ray blazar candidate J1331+2932
A. Gemes, K. Ã. Gabányi, S. Frey +3
Active galactic nuclei are the most luminous persistent (non-transient, even if often variable) objects in the Universe. They are bright in the entire electromagnetic spectrum. Bla…
A compact radio source in the high-redshift soft gamma-ray blazar IGR J12319-0749
S. Frey, Z. Paragi, K. E. Gabanyi +1
Context. Blazars are powerful active galactic nuclei (AGNs) radiating prominently in the whole electromagnetic spectrum, from the radio to the X-ray and gamma-ray bands. Their emis…
Identifying compact symmetric objects with high-precision VLBI and Gaia astrometry
T. An, Y. Zhang, S. Frey +2
Compact symmetric objects (CSOs) trace the earliest phases of radio-galaxy growth; however, robust classification is difficult when radio cores are weak or invisible. We aim to dev…
EMU Radio Observations of Barred Spiral Galaxy NGC 5938 (Araish)
H. Zakir, M. D. FilipoviÄ, L. Barnes +14
We present multi-wavelength observations of the nearby spiral galaxy NGC 5938 (Araish) to investigate the origin of its radio emission, specifically the contribution from active ga…
Gamma-ray-emitting quasar 0202149: a CSS revisited
T. An, Y. -Z. Cui, W. A. Baan +2
PKS 0202149 is a low-power radio source with blazar-like -ray AGN characteristics and its properties and classification are investigated in relation to its -ray characte…
Four hot DOGs eaten up with the EVN
S. Frey, Z. Paragi, K. E. Gabanyi +1
Hot dust-obscured galaxies (hot DOGs) are a rare class of hyperluminous infrared galaxies recently identified with the Wide-field Infrared Survey Explorer (WISE) satellite. The maj…
Tidal Disruption Events with the SKA
T. An, A. J. Goodwin, J. C. A. Miller-Jones +3
The paper outlines how the Square Kilometre Array’s sensitivity, wide frequency coverage, and VLBI capabilities will enable large‑scale radio studies of tidal disruption events, im…
Radio Properties of the -ray Emitting CSO Candidate 2234+282
T. An, Y. -Z. Cui, K. E. Gabanyi +3
Most of the gamma-ray emitting active galactic nuclei (AGN) are blazars, although there is still a small fraction of non-blazar AGN in the Fermi/LAT catalog. Among these misaligned…
Radio structure of the blazar 1156+295 with sub-pc resolution
W. Zhao, X. -Y. Hong, T. An +4
1156+295 is a flat-spectrum quasar which is loud at radio and gamma-ray. Previous observations of the source revealed a radio morphology on pc to kpc scales consistent with a helic…
Parsec-scale jet properties of the quasar PG 1302102
P. Mohan, T. An, S. Frey +3
The quasar PG 1302102 is believed to harbour a supermassive binary black hole (SMBBH) system. Using the available 15 GHz and GHz, multi-epoch Very Long Baseline Array data…
Multi-wavelength properties of three new radio-powerful quasi-stellar objects discovered from RACS
L. Ighina, A. Caccianiga, A. Moretti +12
We present a multi-wavelength study of three new quasi-stellar objects (QSOs) identified from dedicated spectroscopic observations. The three sources were selected as hi…
Tracking the curved jet in PKS 1502+106
T. An, X. Y. Hong, T. Venturi +2
We carried out a multifrequency and multiepoch study of the highly polarized quasar, PKS 1502+106 at radio frequencies. The analysis is based on an EVN dataset at 5 GHz, archive VL…
High- radio Quasars in RACS I: Selection, identification, and multi-wavelength properties
L. Ighina, A. Caccianiga, A. Moretti +21
Radio-bright, jetted quasars at serve as unique laboratories for studying supermassive black hole activity in the early Universe. In this work, we present a sample of high-$z…
Evolutionary Map of the Universe (EMU):Compact radio sources in the SCORPIO field towards the Galactic plane
S. Riggi, G. Umana, C. Trigilio +26
We present observations of a region of the Galactic plane taken during the Early Science Program of the Australian Square Kilometre Array Pathfinder (ASKAP). In this context, we ob…
Extreme Superluminal Motion in the Curved Jet of PKS 1502+106
T. An, X. Y. Hong, T. Venturi +2
In this paper we present a multifrequency and multiepoch study of \object{PKS 1502+106} at radio frequencies. The analysis is based on an EVN (European VLBI Network) dataset at 5 G…
Compact radio emission indicates a structured jet was produced by a binary neutron star merger
G. Ghirlanda, O. S. Salafia, Z. Paragi +33
The binary neutron star merger event GW170817 was detected through both electromagnetic radiation and gravitational waves. Its afterglow emission may have been produced by either a…
GaLactic and Extragalactic All-sky Murchison Widefield Array eXtended (GLEAM-X) survey II: Second Data Release
K. Ross, N. Hurley-Walker, T. J. Galvin +9
We present the second data release for the GaLactic and Extragalactic All-sky Murchison Widefield Array eXtended (GLEAM-X) survey. This data release is an area of 12,892-deg^2 arou…
No apparent superluminal motion in the first-known jetted tidal disruption event Swift J1644+5734
J. Yang, Z. Paragi, A. J. van der Horst +5
The first-known tidal disruption event (TDE) with strong evidence for a relativistic jet -- based on extensive multi-wavelength campaigns -- is Swift J1644+5734. In order to direct…
Very long baseline interferometry observations of the high-redshift blazar candidate J0141-5427
K. Ã. Gabányi, S. Belladitta, S. Frey +7
Active galactic nuclei (AGN) have been observed as far as redshift z~7. They are crucial in investigating the early Universe as well as the growth of supermassive black holes at th…
Constraining the radio jet proper motion of the high-redshift quasar J2134-0419 at z=4.3
K. Perger, S. Frey, K. Ã. Gabányi +12
To date, PMN J2134-0419 (at a redshift z=4.33) is the second most distant quasar known with a milliarcsecond-scale morphology permitting direct estimates of the jet proper motion.…
VLBI imaging of the pre-coalescence SMBHB candidate SDSS J143016.05+230344.4
T. An, Y. Zhang, A. Wang +7
Context. Recently, SDSS J143016.05+230344.4 (J1430+2303) was reported to be a supermassive black hole binary (SMBHB) in the final coalescence phase. It is probably the first SMBHB…
Detection statistics of the RadioAstron AGN survey
Y. Y. Kovalev, N. S. Kardashev, K. V. Sokolovsky +57
The largest Key Science Program of the RadioAstron space VLBI mission is a survey of active galactic nuclei (AGN). The main goal of the survey is to measure and study the brightnes…
The Submillimeter Array 1.3 mm line survey of Arp 220
S. Martin, M. Krips, J. Martin-Pintado +7
We present the first aperture synthesis unbiased spectral line survey toward an extragalactic object. The survey covered the 40 GHz frequency range between 202 and 242 GHz of the 1…
Panning for gold, but finding helium: discovery of the ultra-stripped supernova SN2019wxt from gravitational-wave follow-up observations
I. Agudo, L. Amati, T. An +96
We present the results from multi-wavelength observations of a transient discovered during the follow-up of S191213g, a gravitational wave (GW) event reported by the LIGO-Virgo Col…
A fast X-ray transient from a weak relativistic jet associated with a type Ic-BL supernova
H. Sun, W. -X. Li, L. -D. Liu +163
Massive stars end their lives as core-collapse supernovae, amongst which some extremes are broad-lined type Ic supernovae from Wolf-Rayet stars associated with long-duration gamma-…
J1110+4817 -- a compact symmetric object candidate revisited
M. Krezinger, S. Frey, T. An +2
Compact symmetric objects (CSOs) are radio-emitting active galactic nuclei (AGNs) typically with a double-lobed radio structure confined to within 1 kpc. CSOs represent the earlies…
Capabilities and prospects of the East Asia Very Long Baseline Interferometry Network
T. An, B. W. Sohn, H. Imai
The very long baseline interferometry (VLBI) technique offers angular resolutions superior to any other instruments at other wavelengths, enabling unique science applications of hi…
A parsec-scale faint jet in the nearby changing-look Seyfert galaxy Mrk 590
J. Yang, I. van Bemmel, Z. Paragi +9
Broad Balmer emission lines in active galactic nuclei (AGN) may display dramatic changes in amplitude, even disappearance and re-appearance in some sources. As a nearby galaxy at a…